His fault or mine?

Chloe

My boyfriend and I tried to have sex for the first time last night, and after being erected for a bit we decided to put the Jonny on, however as soon as we did, it went down. To me the condom looked too tight but I don’t know if this would have been a cause but my boyfriend felt bad. Myself when I checked I had tightened up which will have made it harder for it to go in...any suggestions of what we can do?