Of course you can. But don't.
You asked him out and told him when you are available. Your work is done. The ball is in his court now. If you contact him again, yes, you risk appearing pushy and/or desperate. That won't help the situation.
I usually say that life is short and you should go for what you want, but you've already done that. It's his move.
Don't contact him again. Just go enjoy your vacation.