Don't think I saw any obviously fake profiles but I did see some hilarious ones. My favorite was a woman in her mid-40's who included a photo of her smoking a blunt in the bathtub (with an emoji covering her nipple) and an anecdote about blowing Matt Dillon in a public park- best part is that she went out of her way to point out that this was in the 80's so Matty Boy was at the peak of his hotness. Kinda regret not going out with her TBH.
I'm monogamous by nature too but sorta fell into a semi-poly type situation awhile back, partly because the main woman I was dating wasn't honest about the extent of her poly-ness. But again, this is common these days- if you ask around, I'm sure your friends have experienced it. Anyway like I said, it's all a learning experience and also a social experiment, hopefully having fun and getting laid while getting closer to what you're actually looking for.