Had a fling with Sarah Marx
History: Diego always had a thing for Heather, but when her sister Sarah came to town, he realized that they had more in common. Diego and Sarah had been friends for a while, but once Kyle and Sarah split up for a while, the two slept with one another and after a series of lies between Sarah and Kyle, the truth came out about her time with Diego. When Sarah's true nature was revealed, Diego walked away from her (as did Kyle) and right now Diego is awaiting a paternity test to see if he's the father of Sarah's baby.
Dated Cori Warner
History: Cori has always had a crush on Diego from when she was a little girl. Unfortunately for Cori, Diego has always been taken until now. When he and Maria were together, Cori knew she couldn't have him, but now that he's available Cori made it her mission to get up close and personal with Diego. Too bad for Cori that there were two other women in Diego's life and in the end he chose Sarah. After he slept with Sarah he dumped a very angry Cori who later swore her revenge.
Had a flirtation with Heather Gibbons
History: When Heather first met Diego, she thought she'd use him to help her take down rival Avery, but instead she found him rushing to play her white knight when she got wrapped up with Cameron. These two had many flirtacious moments between them, but when Heather married Cameron, Diego backed off. Still that didn't stop Heather from coming to him and in spite of himself Diego started to fall for Heather. These two had an instant chemistry and found themselves drawn to one another despite the obvious differences between them. Diego tried to help her and her son break free of Cameron before Cameron uses Heather's child as a pawn in yet another one of his twisted games. Ultimately Diego wound up sleeping with Heather's sister Sarah and the relationship stopped before it ever started.
Briefly dated Shannon Pryce
   
History: Diego and Shannon met when she was undercover at the hospital watching Deidra. The two immediately hit it off and decided to give romance a try. Unfortunately for Shannon, once again Heather Gibbons got in the way of a relationship and when Shannon learned of Diego's feelings for Heather, it put an end to their romance, but they are still friends. Currently Shannon and Diego are both experiencing issues with the romances in their lives. Could they find their way towards one another again down the road?
Is close friends with Barbara Wilson
   
History: Although Barbara has had a crush on Diego for a while it seems he's clueless where her heart is concerned. She's been his shoulder to cry on, but she's hoping that one day he'll see her as something more.