Should I tell them?

Well if they have told before then don’t tell them. If you want to ask him out, but are nervous, then just invite him somewhere! Not on a date to start with, just invite him to laser tag or something he likes, just as a friend. Tell him that you are going to (insert activity) and want to know if he would like to come along. Pretend that another friend is going with you, then at the place, delay a little after he arrives, then pretend to receive a phone call from the other friend telling you that he/she can’t go. The next time make sure others actually do come, so he wont get suspicious, and a while later, ask him to the cinema, and let him know it will be just the two of you this time! If he still doesn’t get the message, tickets to a concert or game are always a safe bet to try again