Act of Affection
An Act of Affection comes in many forms.
Pinching someone's cheeks can often be seen as affectionate, admiring how they've grown, or gently teasing them for being cute.
The act of two individuals resting their foreheads against each other's can be very intimate. Occasionally it is shown to be one character leaning their forehead against any part of another's body. In the X-Files fandom, this can be known as Forehead Sex.
This can take place when one 'fixes' another's hair, weaves their fingers into their hair, or simply lays their hand against it lovingly.
Brushing Hair Behind an Ear
Giving a Noogie
Giving a noogie to someone means rubbing your fist against their scalp and hair. It can often be mildly painful, but is usually considered to be an affectionate form of teasing.
A common kink is also hair pulling and though it is sexual in nature and may be associated with Pain Kink, can still be done affectionately.
Hiding One's Face in a Neck
This can be done out of shyness, to hide the emotions on one's face, or just to feel close. If the other person tucks their face into their neck, this can be a form of providing comfort.
This is the act of an individual sitting in another's lap.
Lifting a Head by the Chin
The act of an individual resting their nose against another can be very intimate, and a soft form of affection or neediness. At times two characters will touch their noses to each other's. And when rubbed together gently is given the name: Eskimo Kiss. Though Eskimo is not considered to be a politically correct term, there is no such kiss in the Inuit culture.
Picking an individual up is much like the act of carrying them, only it is a stationary action.
A piggyback ride involves carrying someone, specifically on one's back.