A few sets into your workout, you notice that your muscles feel heavier and
that they look different, too: bigger, fuller, more veiny. This is the blessed
pump, a sensation that Arnold Schwarzenegger once compared to orgasm.
(We assume he was kidding. If not...well, let’s just say we feel even more
sympathy for Maria.) Here’s how to get the pump: For each muscle group,
do three to four sets of 10 to 15 repetitions using light weight, resting 40
to 60 seconds after each set. This works great for the beach muscles -
chest, shoulders, arms - but it’s really exhausting for the bigger leg and back
muscles.

Source: Men's Health Magazine

Stare at her breasts. How can you tell if your mate is faking:?
If a woman is aroused, her breasts swell - in some cases 50 percent larger
than their normal size. "Then, when she has an orgasm, they deflate like a
balloon," says Judith Seifer, Ph.D., a sex therapist in West Virginia. "The
pupils of her eyes will also dilate for 3 to 4 minutes after orgasm because
of hormonal excretions. And if she shies away and can't enjoy any more
clitoral stimulation, that's a good sign she's had an orgasm."

Source: Men's Health Magazine