Sexting virgin

So I've been with my bf for a bout a year now and we're having a baby together.He wants me to sext him while I'm at work and I don't know why but I think it's a lil awkward and I don't know what to say. We've been together a while so it shouldn't be awkward.I've never sexted before and he keeps trying to get me to and I don't know what the hell to say,I feel rediculous, and I'm annoyed lol so help? 😂