● Probably being a commoner or bastard. Royalty could be performed as well, but Oberyn wouldn't care your statis prior to marriage.
● Him being incredibly sweet and passionate with you. Caring beyond all doubts.
● Lots of sex. Lots of orgies. But most importantly lots of love.
● Having to understand that he loves you, but he would have other partners. But you would always be his number one.
● Being disrespected by Cersei every step of the way while at the wedding for Joffery and Tywin's eyes lingering on you for a moment longer than you'd like.
● Showing him support for his goals to have revenge for his family.
● Being showed public displays of affection constantly no matter where or when.
● Having many, many, many children by him.