Here are some country songs I really like. Brad Paisley has a lot of very cutesy ones but I just grabbed a few I liked. Please note that the lyrics listed are only examples of the mood of the song, it's best to explore the songs and find what best fits you, for instance, if you guys are fairly new and have only just started the "I Love You"s then Brad Paisley's "Come on Over Tonight" would be a much cuter/better song than "I Hope That's Me" which is about being together forever.
"Hold that Thought" (Close your eyes, picture this, lying in bed in the candle light, we start to kiss)
"I Hope That's Me" (Old man on the front porch swing, looking back on his long life, glass of ice tea in his hand, other arm around his wife. I hope that's you, I hope that's me)
"Love Is Never Ending" (Seasons come and seasons go, One day sun, the next day snow, Flowers die and flowers grow, But love is never-ending)
"Forever and Ever, Amen" (I'm gonna love you forever, forever and ever, amen)
"Don't Mind If I Don't" (Ohh, I keep thinkin' I might stay here, By your side and watch the green grass grow, Oh, I got places to be, people I need to see, Girl, I really should go But don't mind if I don't)