Hopefully by the point you're getting up close and personal, your partner is comfortable with the concept that you have diabetes and wear a pump.
The first time I had sex with a pump on, I disconnected but left my site in... I told him to strategically avoid too much contact with that particular part of my hip/back and It was no problem.. I didn't think about it too much. The more experience I gained, the more I just took it out and did a site change. Not always...just if it happened to be the day I was doing a change-out anyway. And honestly, I always prefer sex without a pump. But! I prefer everything without a pump and after 6 years with a minimed, I went back to multiple injections and couldn't be happier.
For what it's worth, I have friends who don't even disconnect and they claim to have no trouble. You figure out what's right for you and your partner and play it by ear.
When I had the pumps that I could take off, I would just take mine off like I would when I took showers. Most of the time they would not notice or not say anything. But when they asked I gave a quick answer, continued and explained later. It was never an issue.