I could never consistently tap my foot and play until I learned to play drums. Then, after having played drums awhile, I finally "got it" about the foot tapping thing. A real "Ah ha!" moment, lol. If you can do it, it really helps. However, if you can’t do it, you take a easy enough natural playing situation and unnecessarily make it more awkward by making it necessary to divide part of your attention to keeping your foot going in time — in such case, it actually complicates things and can make one’s playing worse.
So, I’ve seen these clouds from both sides now, so to speak. As has been mentioned, moving your body (such as, playing with knees slightly bent, swaying your hips and dipping a shoulder in time with the music; or maybe just moving a knee back and forth; or bouncing up and down a bit; head movements; etc., can all have a similar effect and can be a cool visual thing on stage, too. But there is something about tapping one’s foot once you learn to do it.
I’d tell the band leader that I will absolutely start gradually incorporating foot tapping in some of my practicing time, and I appreciate that tapping one’s foot while playing is a long-established, very commonly used technique for helping and maintaining playing with timing, but right now it’s actually complicating things for me. What I want to do instead is use bigger body movements, which is actually more in line with what a bass hopefully does (stereotypically, the bass is the instrument that gets the booties shakin’), and something that a number of bassists have recommended to me. But, like I said, I will work on my foot tapping while playing, but please understand that it’s something that’s going to take some time.
[Of course, you know him and your relationship best, so if this is how you decide to handle it, put it however you think would work best between you]. Best of luck however you decide to proceed!