Do I choose conditional offer or US on may 1?

So US universities make you make the decision by May 1, but if I get into a UK university that I wanted based on a conditional offer, but then get rejected because I didnt make the conditions, can I crawl back to the US university?
I hope that made sense. I havent even applied or anything yet, but I’m worried about that scenario.
I’m applying for class of 2020.

I believe you can accept the US offer on 1 May, and then not go if you get your UK conditions and prefer that offer. You would lose your deposit.

Exactly right. On 1 May, you have to pay the deposit, which is specifically designed to ensure that you will be hurt if you change your mind, but if you do not mind losing the deposit, then that is fine.