The term coined when a man rubs one out into his lovers eyes whilst she/he sleeps. The semen then hardens as the lover sleeps blissfully unaware of the surprise waiting for her/him when they awake.
The term "spalding" originated from an unknown source, but has become a popular name for this most beloved of sexual pranks.
Matt jizzed into Doug's eyes whilst he was sleeping. The next morning, Doug awoke to find that he couldn't open his eyes. Trying to remove the crispy and slightly sticky residue from around his eyes, his fingers and face got all gunked up.
Matt gave Doug a very nice spalding last night after a lovers tiff!