Boyfriend suddenly wants to use condoms

this seems tmi to write, but it's been bothering me and this seems like a good place to get opinions. my boyfriend and I have been living together for a year and seven months. I've been been on birth control since before I met him. We only used condoms at the beginning. He's a very sexual person. A couple months ago he said he had a reaction to using coconut oil to masturbate. We went a few weeks without having sex and i was fine with it, but it was weird since because he always wants it. When we started having sex again, he wore condoms to keep his dick from getting irritated and no oral. he also always wore underwear. he said it was to keep the base from getting irritated. When he said he was completely better, he still wanted to use condoms. I asked if u could give him oral again and he said he doesn't want that anymore. When I asked why he said from my standpoint it's gross. I don't think it's gross and never implied that. it's one of faves things to do in the bedroom and he knows it. before this all started happening I had thoughts about him cheating on me and getting an STD then giving it to me. im constantly worried about that stuff though I whenever try talking about it, he never really gives an answer and I'm not the type to pry. I did find out last month that he was talking to another girl for a month. they both said they never had sex though. I'm giving him another chance, but all this is bugging me a lot.