1st blowjob???

My SO and have been sexually active for over a month but I've never sucked his dick (or anybodys! He's my 1st for everything) 🙈 idk if im nervous or what but i just really dont want to but i feel bad because i wanna give back to him lol. I tease him alot and he always asks "when are you gonna stop teasing me baby" and my excuse is always " one day 😂 " or " i waiting for a better time " 💀💀 idk help pls ?