TIFU By exploding a balloon on my roommate head while he was in a date

I might actually need to move out but here is my story :

My roommate had been out all evening with this girl he really liked. When I heard the door unlocking, I figured the date was done perfect time for a prank. I had taped a balloon above the doorframe, ready to pop it the second he walked in

Except it wasn’t just him walking in. She was right there. I didn’t realize until it was too late, i pulled the string, and the balloon exploded right above his head that made her scream and jump back. He just froze, all wet

She mumbled something like "what the hell" and left no hug, no kiss, no goodbye. He turned to me, dead silent, and just said "your an idiot" and left to his room

Now I’m sitting here replaying it wondering how I managed to ruin both his date and a friendship in one sec

TLDR: Thought my roommate’s date was over popped a balloon on his head for a prank scared the girl off destroyed the date and my friendship