As he approached to photograph the male and female bird almost appeared to know what was coming.
Mr Foster, 23, a web developer from Manchester, was visiting Chester Zoo last month when he noticed the birds and decided to take some pictures.
He said what happened next was uncanny.
He said: "When I looked back at the pictures it was hilarious, it looked just like a human couple adjusting themselves for a photograph.
"It was very cold and late in the day and the zoo was all but empty as I approached the Humboldt penguin enclosure.
"I was drawn to a male and female who appeared to be very intimate; they were really close together and looked to be petting or cleaning each other.
"As I got closer to them I stopped to compose a shot and they were busy fidgeting and preening one another.
"Then just like that they both turned to look straight at me, it was like they were getting ready for me to take their best picture just like a couple.
"It pretty much made my day and I later found out that most Humboldt penguin pairs remain faithful to each other for years.
"They rarely choose new partners unless one of them dies, and they often return to the same site to breed year after year.
"I like to think these two are lifelong lovers maybe we could learn a lot about relationships from these feathery, faithful birds."
"They seemed perfectly in tune with one another."