Is it weird to ask my fiance if he exchanges memes with his female coworker?

She is a female coworker, only female in the office who he's done lots of favors for (dropping her to the airport, being her dnd, driving her out to lunch, giving her dating advice, listen to her rants about men). One time while we were out at a concert he and I held hands in front of her. He said "I'm pretty sure we made her jealous." A month before he proposed to me, his coworker mentioned that she sent him a meme on instagram. My fiance sends me memes on instagram almost daily. Sometimes it will be a meme about his work, which signals that he may be exchanging memes with her. One time he was texting her and he told me she says hi. I asked to see her text and he said "Why? Do you think she sends me nudes?" I never even brought up that idea so it was weird. He told me he would invite his coworkers to his wedding but did not mention her name. He admitted to me once that he asked a trick question to his coworkers about sex. She was one of them he asked. Overall I don't feel assured that he is not into her. Would it be alright to ask if they exchange memes on instagram?
Is it weird to ask my fiance if he exchanges memes with his female coworker?
Post Opinion