Realise there is often a fine line between friends and friends with benefits. My advise would be let them know you find them attractive like offering compliment

Realise there is often a fine line between friends and friends with benefits. My advise would be let them know you find them attractive like offering compliments. Occasionally make a move to get closer, massage, touching etc. Spend time with them. It is likely they will be in the mood sooner or later and you will be the most convenient option. Basically let them know your interested and ask. If you don't ask you won't get anything. But keep it light and occasional. And remember people can change their mind - so its ok to ask more than once.