How does oberon and titania been involved in the past with Theseus and hippolyta, and why have thye come to Athens?

Can you please rephrase this question?

Titania accuses Oberon of having been romantically involved with Hippolyta in the past. He has come to Athens, to witness at her wedding. In turn, Oberon suggests that Tatiana also had some "spirit loving" time with Theseus. The two constantly bicker over the boy left in Tatiana's care by one of her priestesses.

yessssssssssssssssssssssss they fellll in love and got married nd had kids