You can pretty easily find what you’re looking for with the following syntax: OR search:tags:tag,tag2 -tags:unwanted-tag AND search:tags:tag+tag2 -tags:unwanted-tag
This is a bit of an older post but the search works the same:
You can also use tag intersections (this respects your muted tags) example: https://discuss.eroscripts.com/tags/intersection/pov/blowjob
Unfortunately search not respecting muted tags is a bug in discourse, not much we can do about that.