Imagine your F/O relying on you.
Imagine your F/O needing your help when they have a hard task. Maybe for them it's doing something strenuous like moving furniture or doing roofing. Maybe for them it's getting the house clean, or washing the pets. Maybe for them it's clearing a video game level or getting their clothes on in the morning.
Imagine your F/O giving you control of their finances and possessions, knowing it'll all be safe with you.
Imagine your F/O looking to you for protection, emotional or physical. You're strong, body and mind, and they know they can trust you.
Imagine you're the first person your F/O turns to when there's a problem, because you're the very first person they can say they 100% trust.
Imagine your F/O relying on you.