Word or phrase for one who tries to benefit from everything someone else does [duplicate]

I am trying to find a good word or phrase to describe someone who (or the act of someone which) tries to benefit from everything someone else has or does.

The context is, on a personal level.

For example, a friend, parent or someone else tries to be included in all of the good things that come out of your hard work.

A more concrete example may be "My friend Sam is always pushing to drive my new car, stay at my new house, go out when I get paid knowing I'll pick up the tab, inviting herself and her child to any of my interesting outings for the child's benefit. Sam is ______".

I do want to make the distinction that this should not be strictly related to money. It's just one person who uses someone else's advantageous situation to benefit, at every possible opportunity. The word/phrase I am looking for should describe either that person or their act.

Leech. While the biological leech is a parasite, the metaphorical meaning does not require actual damage to the host. It is characterized by attaching oneself to the accomplishments of a host and not doing significant efforts of one's own.

parasite src: ODO

2 derogatory A person who habitually relies on or exploits others and gives nothing in return:
the capitalist is really a parasite on the workers
etym: … '(person) eating at another's table' …
syn:
hanger-on, cadger, leech, passenger, drone
informal bloodsucker, sponger, sponge, scrounger, freeloader
British informal ligger
North American informal moocher, mooch
Australian/New Zealand informal bludger

There may be a better word or phrase more closely fitting the OP's need, though.

Sponge and moocher come to mind.

From http://www.thefreedictionary.com/moocher

mooch (mo͞och) Informal v. mooched, mooch·ing, mooch·es v.tr.
1. To obtain or try to obtain by begging; cadge. See Synonyms at cadge.
2. To steal; filch.

v.intr.
1. To get or try to get something free of charge; sponge: lived by mooching off friends.
2. To wander about aimlessly.
3. To skulk around; sneak.

n.
1. One who begs or cadges; a sponge.
2. A dupe, as in a confidence game.

One word that comes to my mind is free loader and another word is the movie called friends with the benefits

Searching for a single word is bound to be unsatisfactory. However, if you described your friend as "pushy" (not worried about being polite to get what she wants) and "insinuating" (forcing herself into situations where she may not be welcome) most people would get the gist.