These are two Steatoda borealis, happily coupling: male is on the left, female on the right.
If you’re confused about what’s going on, it helps to know that spiders are acrobatic, they don’t care much about up or down. Also, every time I catch S. borealis in the act, they mate face-to-face, with the male sliding his long palps equipped with multiple hooks underneath her jaws to lock onto her abdominal genital opening. Now you can tell what’s going on, right?