Hands-on experience

When undergoing an, erm, gentleman's check-up and the doctor prefaces his duties with the words "May I?", what's the correct response? "Absolutely" might be construed as overenthusiastic. "By all means" doesn't seem quite right, for the same reason. Likewise "Be my guest" and "My pleasure". Perhaps in the circumstances a simple, curt "Yes" while avoiding all eye contact is best. Worth remembering for next time.