Here's a thought. It takes me longer to ejaculate as I get older. Especially after I have recently ejaculing several times during the day or the day before. Sometimes there is not enough friction during penetration to stimulate me enough to ejaculate. The lack of friction is because my partner is very excited, which means she is very wet and not tight. Maybe your boyfriend needs more friction. Anyhow, I would not equate the number of orgasms you have with his. If he's okay with it, then you should be to and just enjoy it.