State two instances which tells us that Pluto loved his wife, Proserpine, dearly.

In Ovid's Metamorphoses, Pluto is described as loving Proserpine from the moment he sees her (and with some help from Cupid):

While Proserpinewas playing in this wood, picking violetsand shining lilies, and, like a young girl,was keen to fill her baskets and her lap,trying to gather more than anyoneof her own age, Pluto caught sight of her and, in almost the same instant, loved herand carried her away—that’s how rapidlove can be.

Unfortunately, Pluto chooses to kidnap Proserpine and take her with him to the underworld without the consent of her or her mother Ceres. This leads Ceres to search and search for her daughter. The poet says "She searched the entire world in vain." Once Ceres discovers that Pluto has stolen her daughter, Jupiter, Proserpine's father, claims that it's "not a criminal act . . . this is love."
Beyond the explicit notes in the poem that Pluto takes his wife because he loves her, we could infer that his allowing her to go up to the earth for half of the year to spend time with her mother is an act of love. Knowing how close mother and daughter are, he would also understand how much happiness he could give his bride by letting her be with Ceres again.