Good first effort
Slice of life, May December romance, novella, adult situations
Plenty of buildup for the characters. Some things are raised as things that need doing, but then fall by the wayside. Either a few sentences here and there to deal with or omit them entirely. A good rule is if you introduce things, they need to be dealt with. A bigger point, a bungalow can described as a cottage, but not as an apartment.
Both have baggage to handle, but they didn't even talk about birth control with Cole making assumptions. It's okay to skip that for the story, but in real life therein lies the potential for misunderstanding and accidents.
There were hints of potential seriousness, but the ending threw that into question, making Savannah's shift from possible long-term commitment to a summer or college affair; polyamory may be fantasy, but in practice it takes a lot of honesty and communication to work, and we don't know enough about either to really comment meaningfully.
Better to spell out "okay" fully. Acronyms, like internet slang, should also be explained, as the older set (myself included) won't know what you mean. You could have had Cole ask for an explanation; a former COO will normally be computer savvy, at least for email, word processing, and even spreadsheets, but is less likely to be aware of internet slang terms.
Some hopefully useful notes on anatomy: single thrust full penetration is only possible after proper initial stretching (3-4 thrusts are usually sufficient). At rest, the sheath is on average only about three inches deep. Just as men will vary in size, so women will vary in their ability to accommodate their partner, with five to six inches being the norm for both sexes. Once stretched, the sheath will remain dilated for about five minutes after withdrawal before slowly contracting back to its normal resting state. The body is amazing!
Again, good first effort. Excellent editing. Overall, enjoyed. Wishing you good luck on your writing career!