Christina Aguilera posts TOPLESS photo of her boobs being cupped by fiancé Matthew Rutler

Christina Aguilera posted a smoldering photo on Thursday in which she posed topless while her fiancé Matthew Rutler grabbed her breasts from behind.

While modeling a kinky metallic mask, her husband — who met her when he was a production assistant on her 2010 film Burlesque — wore a suit.

The blonde 42-year-old singer wished a happy 38th birthday to Matthew, to whom she has been engaged since 2014.

In a heartwarming Instagram montage that recalls their years together, Christina made sure to include a photo of him rocking their eight-year-old daughter, Summer.

“Happy birthday baby love life with you,” she wrote in the caption, adding a silver heart emoji for good measure.

Look of love: Christina Aguilera posted a smoldering photo on Thursday in which she posed topless while her fiancé Matthew Rutler grabbed her breasts from behind

During the course of the video, she also showed a few pictures of Matthew during his childhood and teenage years, long before he met Christina.

In the midst of a few red carpet photos, Christina tossed a particularly romantic photo of her and Matthew staring into each other’s eyes on the beach.

She recently dropped her jaw when she made a series of brutal revelations about her experimental sex life on an X-rated episode of the Call Her Daddy podcast.

During the chat, the Dirrty hitmaker, 42, revealed she had sex on a commercial flight “under covers” and “bent over on a soundboard” in a music studio.

Soon after, she ended up shocking host Alex Cooper by professing her penchant for a specific sexual act.

Xtina started the chat by revealing that she loves performing fellatio, saying it’s “very important to be with a partner that you can really explore.”

She said, “Sexuality is a very specific thing, so what one man likes, another doesn’t” – while adding intimacy has “many different levels.”

The star also described losing her virginity, saying, “It’s so funny I gave this persona because I was probably the last person to lose my virginity.

Big day: The blonde 42-year-old singer wished a happy birthday to Matthew, to whom she has been engaged since 2014

Big day: The blonde 42-year-old singer wished a happy birthday to Matthew, to whom she has been engaged since 2014

Baby mine: In a heartwarming Instagram montage remembering their years together, Christina made sure there was a photo of him rocking their eight-year-old daughter Summer

Baby mine: In a heartwarming Instagram montage remembering their years together, Christina made sure there was a photo of him rocking their eight-year-old daughter Summer

Having a ball:

Having a ball: “Happy birthday baby love life with you,” she wrote in the caption, adding a silver heart emoji for good measure

Is it in his eyes?: Amid a few red carpet photos, Christina tossed a particularly romantic photo of her and Matthew staring into each other's eyes on the beach

Is it in his eyes?: Amid a few red carpet photos, Christina tossed a particularly romantic photo of her and Matthew staring into each other’s eyes on the beach

Looking back: Over the course of the video, she also showed a few photos of Matthew during his childhood and teenage years, long before he met Christina

Looking back: Over the course of the video, she also showed a few photos of Matthew during his childhood and teenage years, long before he met Christina

Letting it all hang out: Christina recently revealed she had sex on a commercial flight 'under covers' and 'bent over on a soundboard' in a music studio

Letting it all hang out: Christina recently revealed she had sex on a commercial flight ‘under covers’ and ‘bent over on a soundboard’ in a music studio

Want to get naughty!  Aguilera gasped when she made a series of brutal revelations about her experimental sex life on an X-rated episode of the Call Her Daddy podcast

Want to get naughty! Aguilera gasped when she made a series of brutal revelations about her experimental sex life on an X-rated episode of the Call Her Daddy podcast

“It was something that was for me. I guess that’s why my posts went that way too, because I may have owned it first.

“It was later than you’d think considering the girl who did Dirty and all that stuff. It’s more funny to look back.’

The star said that because she traveled a lot as a musician, she “didn’t really have time” to date other celebs, saying, “My fears might not take someone who was doing the exact same thing as me.” I know how this goes. I’m too vulnerable.’

Christina and Matthew first started dating in 2009 when they met on the set of her movie Burlesque starring Cher.

In 2010, she gushed about him on People. Matthew is a special person. We had a really strong friendship in the movie,” she began.

“He’s the kind of person you can talk to on the phone for hours and then suddenly it’s daylight.

“I once filed for divorce [from Jordan Bratman], we started dating. I’m not trying to jump into anything. I just left a five year marriage. I’m taking it easy and trying to be happy.’

She added, “There’s a love there, yes. I’m having fun, I’m dating and it’s something I haven’t had in a long time.”

They then welcomed a daughter named Summer Rain Rutler in 2014. The child is now nine. She is also mother to son Max, 15, from her marriage to Jordan Bratman.

Dirrty: The star also described how she lost her virginity, saying,

Dirrty: The star also described how she lost her virginity, saying, “It’s so funny I gave this persona because I was probably the last person to lose my virginity”