Is it normal to like tickling during foreplay and sex?

My girlfriend and I have been together for a couple of years and I've always loved tickling her. Sometimes it's "normal" (non-sexual) tickling just to tease her. Other times though I'll tickle her during foreplay or even during sex. We just started tying each other up and I tickle her really bad when it's her turn. She puts up with it and I make sure to go above and beyond when pleasuring her because she's willing to indulge me. Is it normal to get so turned on with tickling her? I don't want to overdo it and have her tell me not to do it anymore.