Does anyone know if there is a tag for a situation like this? If not there needs to be one!
rule34.xxx/index.php?page=post&s=view&id=8060054
rule34.xxx/index.php?page=post&s=view&id=8073698

It's a bit too specific for a tag. There's really no way to make a tag for something like that that wouldn't end up being an amalgamation of several other tags.

You could, however, make a pool containing such images, like how the comic itself has this one:

rule34.xxx/index.php?page=pool&s=show&id=27920

What situation, exactly? If you mean being stuck together and having to bear with it, I guess 'stuck_together' could work as a tag. It would perhaps be a bit general, but I think it would still be specific enough to be useful in combination with other tags, and not end up as an amalgamation.

If you mean someone sitting on another person with his penis between their legs, then I guess 'sitting_on_person' or 'sitting_on_lap' together with 'thighjob' or 'thigh_sex' should do the trick.

Edit: Okay, I see 'stuck_together' already exists! It seems to be used for various situations where people are stuck together, so more or less what I imagined. And it does seem to have a pretty wide scope... from a quick look, I've seen many pictures of conjoined twins, knotted ferals/anthros, and people staying together in a very confined space. I still think it's useful if you take care to specify some other tags, or filter out the ones you're not interested in. But I wonder if we could think of anything more precise...

By the way, if you have an idea, you're probably better off bringing it up in the sticky Tag Discussion Thread (forum #12809).