is this a bad thing?

so my bf and i have been having sex for maybe two years or so now and when we first started having sex he’d last so long. like when we first started doing anything w each other he would last so long like i’m talking like 40 min long and then sometimes go for another round like an hour later type beat yk? and now, i’ll give him head before, which ive always done, but now, i kid you not the last time we had sex he lasted maybe one song…and that might be exaggerating…and like idk how to ask him “hey um why don’t you last in bed w me anymore?” bc i know that’s a huge thing for dudes yk,,idk doe anyone have any thoughts on what i could do to spice things up and make it more fun? or if there’s something that i’m doing wrong? lmkkkk oh and he also said he rlly only likes doing doggie bc “booty” and we use to switch positions allll the time yk and like if i say certain things he finishes like way faster,,but i like making him feel good so..anyways sorry this is so long lol hope you can help!! :))