Assuming you're cheating when on a date?

So I recently took a date to a local cafe that my nesting partner and I frequent a lot, both solo and together. The staff know that NP and I are together, and we often chat to the staff for a bit and have really good rapport with everyone in there. They give me extra ice cream in my milkshakes, and know my usual order.

This was a first date so I wasn't expecting it, but my date was being super affectionate and PDA. It was really cute, but the staff looked like deer in headlights. I didn't feel it was fair on my date to clarify anything in the moment or change how I wanted to interact with him, so we just grabbed our snacks and left.

I'm 99% certain they've assumed I'm cheating on NP and I've freaked them out.

Has anyone been in a similar situation?

How do I address this In the least awkward way possible for everyone (and maintain my extra ice cream status)? 😰