My guy friend wants to hang out alone with me, even though I have a boyfriend, what are his intentions?

We’re pretty close friends and there’s never been anything romantic between us, but sometimes I feel like he doesn’t have great boundaries.

Recently, he invited my boyfriend and me to dinner, but then told me that since we work near each other, he wanted me to go to the restaurant with him — which basically means my boyfriend would have to go alone. It made me feel kind of uncomfortable.

Am I overthinking this, or is that a bit weird?

Updates
8 mo
Thanks to everyone for your input — I read each comment carefully. I decided not to go with him, I' m no longer confused by his 'intension', and I feel like I made the right choice.
My guy friend wants to hang out alone with me, even though I have a boyfriend, what are his intentions?
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