And his children with ex-wife Elin Nordegren tagged along, too. Vonn's contact with the children is seen as a sort of stamp of approval from Nordegren, especially after spending time together on multiple occasions.
Vonn has also been seen taking Woods's children to school in Palm Beach without Nordegren or Woods present, I4U reports.
She has to have given her approval -- the divorce settlement between Elin and Tiger stipulates that he is not allowed to have the children around any new girlfriends or dates without her explicit approval.
That includes female members of Tiger's staff but exempts married women not linked to Tiger's love life.
Recent reports have shown that the couple has moved in together at Woods' home in Jupiter Beach, Fla. and have talked about a prenuptial agreement and getting married. They officially announced their relationship in March.
Swim Week Miami Beach 2014 [PHOTOS]