Jennifer Lopez Flaunts Toned Tummy in London With Casper Smart: See 15 of Her Sexiest Abs Moments (GALLERY)
Jennifer Lopez may be the mother of twins, but she's still got those rock-hard abs from her "Jenny From the Block" days.
Donning a midriff-baring black top that gave way to her sculpted physique, the "On the Floor" singer, 43, strolled side-by-side with her dancer beau Casper Smart as she prepared for her concert on Monday.
Lopez is known to work hard for her enviable flat belly -- even going to great lengths to train with fitness guru Tracy Anderson.
"We don't want her natural beauty to go out of balance," Anderson told People of Lopez' workout regime. "[Overly] ripped abs would ruin her look."
However, another part of her body may have received even more attention that night during her London town concert.
Click through our gallery above to see more skin with J.Lo's 15 sexiest ab moments.